Prevent bacterial growth. Because children's immunity is not as strong as that of adults, kindergartens kill them two or three times a day to ensure that there will be no bacteria breeding and ensure the health of students. Kindergarten, formerly known as Kaner Garden, was introduced from Prussia hundreds of years ago. Formerly known as nursery and kindergarten, it is a kind of preschool education institution, which is used for centralized care and education of children and usually accepts children aged three to six.